Furnace thermostat switch



' l. E. SMITH v FURNACE THERMO STAT SWITCH Filed May 26. 1925 a Sheets-Sheet 1 i 11a 1: C a 5 17 9 f5 I u ..I i I I INVENTOR ATTO R N E'Y QM mm" July 27 1926. 1,594,020

I. E. SMITH FURNACE THERMOSTAT SWITCH 7 Filed May 26. 1925 5 Sheets-Sheet 2 INVENTOR Ira EZSmiilz July 27 1926. 1,594,020 I. E. SMITH FURNACE IHERMOSTAT SWITCH Filed May 26. 19216 A s sheets-sheet a INVENTOR 12 4a: E. Smi/ih' ATTORN EY Patented July 27, 1926.

OFFICE.

IRA E. SMITH, O l STOCKTON, CALIFORNIA.

FURNACE THEBKOSTAT SWITCH.

Application filed any as, 1923. Serial Io. $2,901.

plate, a motor for driving the plate and for:-

16 operating a pump to feed oil to the plate; an electric heating element surrounding the plate so that an initial hot zone may be provided adjacent the plate; and electric spark means for igniting the oil'when the'same 20 is initially fed onto the late.

-In the functioning 0 these parts, it is desirable'that the electric oil-burner heat' element shall bevheated to a predeterm'iri e d temperature before the motor is driven,and

that the drivin of themotor (which causes the oil to be ed to the plate) shall com-' .mence simultaneously with the operation of the sparkin means.

The .oil t us fed to the so influenced by the heat ra iated from the oil burner heating element, and at the same time is subjected to the igniting sparks.

This insures quick ignition .of even a low grade of oil, and at the same time prevents .85 any "accumulation of unburntv oil on the It is also desirable that when the late. iiil has been properly ignited the s ark means shall be discontinued, as" its unctioning after such time would be merely a 40 waste of current. It is further desirable that these steps shall becarried out auto-' matically and in sequence when definite and redetermined temperatures are successivey reached without the presence of an operator bein necessary to control the functioning-of t e-difierent features.

. The principal object of my invention therefore is. to provide a thermostat switch,

so constructed t at the above named steps in w the operation of the apparatus are caused to automatically take place in proper temperat'ure' relation and'se once, as soon as the main circuit o the ym 16010865,

produce a thermostat switch that a singlemodel or size of the same will 3 the device will function as well when the late is at once' furnace, so that an In general, my device is a combined electricall and oil-flame heated thermostat switc whose switch-contact actuating member is first heated to a predetermined temperature by electrical means inde ndent of the oil burner, and is so sitioned relative to the burner as to be su jected to the direct heat from the burning oil as soon as the latter is ignited, so that the actuating member is then heated to a further degree. The switch contacts 0 ned and closed by the above described eating of the actuating member are so disposedthat the above described results are obtained.

The switch is so designed that its operation is controlledsolely by variations in temperature,'and no time controlled or'regulating features enter into its construction.

A further object ofthe invention is to so constructed have a very great rangeof temperature control and adjustment without injury to any part; and which will always beand remain uniform its operation regardlessof extreme variations in temperature. That is",

temperature is many degrees below zero as 1t will when 2000 above zero, intermediate temperature.

and at any A third-object is to provide a switch so constructed that adjustments may be easily -made to enable the dilferent temperatures at which the various stesls will take place or stop to be yari'ed at w Another object is to provide contact means inthe switch soarran ed that the Pened when excessive heat is reached in the furpace, said means being also adjustable so motor circuit'of the system wi be 0 that the degree of heat necessary to cause the circuit to be opened maybe varied as may be desired.

11 connection with the switch features of the device I have provided an air-damper regulator, so' .that admission of air to the furnace or flue may be automatically and adjustably regulated according to and by reason of temperature conditions in the predetermined temperature once reache in the furnace may be maintained practically constant. I. I objects- I accomplishby means of .numeral 1 denotes a furnace or fire such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and .claims.

In the drawings similar characters of reference indicate corresponding parts in the several views:

Fig. 1 is a side view of my thermostat switch, showing the same mounted in connection with a furnace and flue.

Fig. 2 is a side elevation of the device detached, partly broken out and 111 section the parts being in their normal or cold positions.

Fig. 3 is a side view of the contact end of the device, partly in section, showing the contact tube unit moved to open certain ones of the contacts.

"'Fig. 4 is a top plan view of thecontact tube assembly and adjacent arts.

Fig. 5 is a sectional plan 0 the adjustable tube supporting. unit.

Fig. 6 isa sectional view ofan ad acent pair of contact tube holding members.

Fig. 7 is a fr entary top lan v1ew of an adjustable mper-contro connection rod Fig. 8 is a circuit diagram showing one manner in which my switch may be used to control the operation of an oil burning system. v

Referring now more particularly to the characters of reference on the drawin the x m which the oil burner'is located, and from which a flue 2 projects upwardly.

My thermostat switch structure comprises an cxpansible tube 3, such as an iron pipe,

of considerable length so that a portion thereof may project into the furnace in the zone of direct heat therein, while the remainder of the tube will be outside the furnace. This tube is mounted in a. fixed posi tion relative to the furnace by a; bracket 4 preferably applied tothe same, adjacent its outer end. At said outer end the tube is connected to a casing 5 in which the contact unit hereinafter described is mounted. This end of the tube is open, but the opposite or furnace end is sealed as at 3 and has fixed therein one end of a non-expansible rod6 of any suitable composition which rejects through the open end of the tube into the' I use this movement, which of course is slight, to operate a multiple switch contact unlt in the following manner:

Turnably mounted in the casing below the plane of the tube 3 and at right angles thereto is a horizontal shaft 8. A substantially radial and horizontally disposed arm 9 projects outwardly from the shaft and away from therod 6, while another arm 10 projects upwardly from the shaft and is bent at 1ts.upper end to extend toward and abut against the adjacent end of the rod 6.

The arm 9 is considerably longer than the arm ,10 so that a sli ht arcuate movement of the outer end of t e latter will impart a proportionately greater movement to the arm 9. Spring means 11 between the shaft '8 and the casing acts to rotate the shaft in a direction such that the arm 10 will be maintained in constant engagement with the rod 6. It will therefore be seen that as the rod recedes into the tube when heat is applied to the latter, the arm 10 will follow the movement of the rod, the shaft 8 will be rotated, and the arm 9 will move upwardly.

Mounted in transversely opposed relation in the casing above the plane of the tube 6 are brackets 11, which su port needle bearing spindles 12 paralle to the shaft 8 which in turn support the opposite ends of a tubular unit 18. y This unit comprises and members 14 and 15 into which the spindles 12 project, and a plurality of intermediate sleeves 16. indeendent of each other and of the end memers. These sleeves are telescopically fitted,

together soas to form a rigid unit, the different parts of which are independently turnable relative to each other on a common axis, as shown in Fi 5 and6. This axis is of course the spind cs 12.

The adjacent ends of alternate pairsof the sleeves 16, where they slide into each other, are provided with circular and opposed recesses as shown at 17. These recesses when the sleeves are fitted together,

engage and surround glass tubes 18, 19 and 20, the tubes being preferably held centrally of their length. These tubes carry switch contacts as hereinafter seen.

Projecting outwardly from the end member 15 and eccentrically located relative to the spindles 12 is a pin 21.- This pin'is connected to a link 22 which extends to a ivotal connection with the block 23 which 15 slidably adjlustable on the arm 9. By this means when t e arm is raised by the rotation of the shaft 8 as previously described, the tube holding unit is rotated likewise ofcourse altering the angle of setting of the tubes relative to a horizontal plane. By altering the position of the block on the arm 9, the extent of rotation of the tube unit with a iven extent of rotation of the shaft 8 may var ed as will e e ident.

Onto the end member 14 is fixed one end of a spiral spring 24, the other end of which is secured to the adjacent bracket 11 This s ring acts against the spring 11, which is the stronger of the two.

The outermost portions of the sleeves 16, on the ends thereof opposite to the recesses v 17, have circumferential slots 25 to receive screws 26 which are secured in the telescoped sleeve and end members thereunder.

The heads of the screws bite against the outer sleeve portions when tightened down, so that normally all the members will be held together to turn as a unit. It will thus be seen that by loosening different screws, rotatable adjustment of said members relative to each other may be had .to any desired. extent within reasonable limits. This enables difi'erent tubes to be set at different angles relative to each other. Also the setting of all the tubes together or as a unit may be altered by adjusting the members 16 as a unit relative to the end member 15, whose position is fixed when the structure is in normal or cold condition. Likewise the pressure of the spring 24 may be varied by adjusting the end member 14 relative to the other parts of the unit aswill-be obvious. In this manner resistance of the unit to turning with the rotation of the shaft 8 may be altered to suit different conditions.

The tube 18 carries two sets of contacts 27 and 28 located near opposite ends of the tube. A certain amount of mercury 29 is sealed in the tube, and the latter is set on a slant so that when in a normal or cold position, the mercury will engage contacts 27.

These contacts are at that end of the tube which will be raised when the tubes turn withthe heating of the tube 3.

In corresponding ends of the tubes 19 and 20, are pairs of contacts 30 and 31 respectivel also normally engaged by mer curv 32 in said tubes.

The tube 19 is set on a slope greater than that of the tube 18 but in the same direction, while the tube 20 is set at a considerably greater slope than both the others, and also in the same direction. a

All contacts have flexible leads 33 extend ing therefrom to binding'zposts 34 mounted on the casing, so. that two connections may be made with main circuit wires, without interfering with freedom of movement of the tubes. I

Moun ted on the tube 3 over a portion thereof outside-ofjthe furnace is an electric heating element 35. This is. in the form of a-jacket completely surrounding the tube,

and in turn is covered by a heat insulating 'gcket 36, so that all heat asdeveloped, will applied directly to the tube. The circuit to this element is controlled by the contacts 27, but onlyindirectly and-while the leads 37' from this-element are connected to cermeat 40 when said circuit is closed.

tain ones of the binding posts 34, they are not connected to the corresponding leads 33 of said contacts 27. i

In Fig. 8, I have shown a manner in which my switch may be used to control the operation of the major features of my oil burning system.

The system includes a rotary burner plate 38, a motor 39 for driving the same and a heating element 40 surrounding the plate. The plate and heating element, which is preferably in the form of a fiat strip, are insulated from each other and are so spaced that if interposed in a suitable circuit, a constant train of sparks will jump across the gap therebetween, as shown in my copending application filed January 14th, 1925, Serial No. 2,396. i

In the operation of this system as set forth in the first mentioned copendingapplication, the electric heat functions first, then the spark means and motor start simultaneously, while the electric heater is cut ofi', and after a certain temperature is reached, the spark is discontinued while the motor of course continues to operate.

by reason of the relay 41, a circuit C from the main line in which both the electric thermostat heater and the electric burner heater 38 are interposed.- Therefore as long as the contacts 27 are closed both electric elements will be heated. Circuit D from the main line has contacts 28 interposed therein. and a. relay 42. This circuit when closed, causes a circuit E from the main line to the motor 39 to be also closed, and said circuit will remain closed as long as the contacts 28 arc'closed.

Interposed in the motor circuit E is another relay 43 whose opening is controlled by the'o'pening of the contacts 31, in the circuit F of which said relay 43 is interposed.

ment (which are insulated from each other), one lead over said circuit term-inating at and being connected to one lead of the motor circuit between the motor and the relay 42. It will therefore be seen that the its .115 I The sparker circuit G connects the main lines with the plate 38 and the heater -ele-.

sparker circuit will not be closed unless the motor circuit is closed at relay 42. It may here be noted that in practice transformers would be interposed in the sparker circuit G,.-.to transform a low to a high voltage current, so that the latter will jump across the gap between the plate 38 and ele A transformer would also be inserted in the heater element circuit C. Such features,

however, form no part of the present invention, in which the circuit is shown simply for the purpose of illustration only.

Intel-posed in that portion of the circuit G which is independent of the motor and heater element leads is a relay 44 which is closed when a circuit H from the main lines and in which the switch contacts 30 are connected, is closed.

In operation when the apparatus is innormal or cold condition the switch contacts 27, 30 and 31 and their res ective relay circuits are closed by reason of the slope of the tubes in which said contacts are located, and which causes the mercury in the tubes to engage the contacts.

Relays 41, 43 and 44 are therefore closed, but only circuit vC is completed, since relay 42 which controls the complete closure of circuits E and G, is open because contacts 28 are open.

Both electric heater elements 35 and will therefore function, but the motor and sparking means will not as yet be 0 erated.

The heater 40 provides only local 'eat adjacent the burner,not suflicient to materially influence the tube 3 thereabove.

The heater 35 however directly applied to said tube supplies suflicient heat to'the same to cause its initialexpansion. This causes the turning of the tube unit, as previously described, sufliciently to cause the slope of the tube 18 to be reversed relative"- to a horizontal plane. This allows the mercury therein to flow to the opposite end of the tube leaving contacts 27 and engaging contacts 28.

The circuit B is therefore broken, causing the relay 41 to be opened and consequently breaking the heater circuit. Atthe same time circuit D becomes closed, closing relay Since reversal of the osition of the tube 18 has not as yet caus a similar reversal of position of the tubes 19 and 20,0wing to the greater initial slope at which the latter are set, relays 43 and 44 are still closed,

Hence the motor and sparking circuits will be completely closed, and the motor and spark means will begin to function.

When the motorbegins to operate oil is fed to the burner plate and this oil is of course readily ignited by the spark means being initially heated by reason of the hot element 40 surrounding the plate.

Heat is then almost instantly generated in the furnace sufiicient to effect the tube 3, which now expands to a greater degree than was the case during the operation of the heater 35. As aresult the tubes are further turned in the same direction as before until the slope of the. tube 9 becom eversed from its original setting, leaving the 66 contacts 30 therein bare.

Circuit 11- is therefore broken and relay 44 open'ed,.causing the spark circuit to be opened and the spark discontinued. This however does not affect the operation of the motor since the relay 43 is not in the motor circuit, and said circuit will remain closed as long as contacts 28 and 31 and relays 42 and 43 respectively are closed.

Now should heat be generated in the furnace to an excessive degree in the event that other fire control devices (not shown in this application) fail to function, the tube 3 will expand to such a!) extent that the tube 20 will finally be reversed in slope, and the contacts 31 will be left bare.

This will cause the breaking of the circuit F, the opening of relay 43 controlled thereby, and consequently the opening of the motor circuit, causing the motor (which controls the fire), to stop.

To cause the movement of the shaft 8 to operate a pivoted flue air intake damper 45' and open the same from a normal, closed position after a certain heat has been attained in the furnace, I connect an arm 46 to the shaft 8, said arm extending radially of the shaft to a point clear of the casing 5. The outer end of this. arm projects into a longitudinal slot 47 in one end of a rod 48, the other end of which is connected to an arm 49 extending radially from the pivot of the dampermounted on the rod 48 adjacent the slot 47, and adjustable longitudinally thereof is a screw 50 alined to engage the arm 46. By adjusting this screw the dis tance the arm must move along the slot before engaging the screw when moving the arm and consequently openin the damper, me. be varied. Therefore di erent degrees of eat may be raised in the furnace before the damper opens and admits cold air.

Once the damper starts to .open its continued opening is of course proportionate to an increase of heat in the furnace.

The damper is preferably of counterbalanced type, so that no great force is necessary to operate-the same.

This damper arrangement enables hot gases to be maintained 1n thefurnace where they are utilized, instead of a considerable percentage going to waste up the flue. This is because with the operation of the burner a draft is created in the flue which increases with the heat. If air can only be taken in from below the burner, a constant draft of cold air moves past the burner to reach the flue, reducing the efl'ect iveness of the fire and causing a quantityof hot gases to'pass up the flue. By means of my arrangement, 7

the draft is therefore not felt so much, below the burner. Only sufiicieut air is then taken in at the latter point to promote proper combustion. The hot gases are therefore retained in the furnace where their heat can be utilized.

From the foregoing description it will be readily seen that I heve produced such a device as substantially fulfills the objects of the invention as set forth herein.

ill

While this specification sets forth in dethe present and preferred construction of the device, still in practice such deviations y from such detail may be resorted to as do not-term a departure from the spirit of the invention, as defined by the appended claims, Having thus described my invention what l clairnas new and useful and desire to secure by Letters Patent is 2' a l. A thermostat switch including a longitudinally erpeiisible tube and a non-expensibie rod therein, a rotatable structure mounted in fired relation with the tube at right ed on the structure and to which the other end of the arm is j ivoted in a plane eccentric with the axis of t e structure, and means for edjustably cleniping the said member with spect to the structure whereby to enable the i be rotated without disturbing the and parts connected therewith,

e thermostat switch, a plurality of the tube held thereby, relative to adjacent sleeves, axial spindles at the opposite ends of the sleeve structure whereby said structure and the tubes may be rotated as a unit, and thermostatically actuated means for thus rotatin said structure.

3. u a thermostat switch, a lurality of longitudinally alincd pairs of s eeves, tubes extending at right angles to and between the sleeves of each pair, said tubes contain iug a quantity of mercury and spaced contacts mounted therein adjacent one end to engage the mercury, means provided with each air of sleeves for engaging and holding t e cert-responding tube, one sleeve of each pair turuably projecting into the adjaceut sleeve of the adjacent pair,=the latter having a circumferential slot, at set screw mounted in the inner sleeve and projecting through the slot to frictiona'lly engage the outer surface. of the slotted sleeve, means for mounting the sleeve structure to enable the same to rotate as a unit, and thermostatically actuated means for thus rotating said structure.

In testimony whereof I afix my signature,

IRA .E. SMITH, 

